Abstract
Gap graded natural sand is widely used in hydraulic structures, foundation treatment and recharge well fillers, and it’s also common in geological structures such as landslide deposits. In order to study the influence of grain shape on its pore and permeability characteristics, river sand in Yichang (YS), standard sand in Henan (HS) and standard smooth glass beads (BZ) are selected as test materials, and the grain shape parameters of three materials are analyzed on multiple scales. Then tests on porosity and hydraulic conductivity of gap graded natural sand were conducted. On this basis, a numerical model considering grain size distribution, coarse grain content and grain shape was established. The results showed that the average values of the shape parameters increased or decreased with the increase of grain size, and the coefficients of variation for the parameters were between 0.026 and 0.208. The shape parameters showed a negative skewness distribution, but the absolute value of the skewness coefficient was small (0.254–0.616). Grain size distribution and grain shape are the main factors controlling the porosity and hydraulic conductivity of gap graded natural sand. The minimum values of porosity and hydraulic conductivity appear at about 70 % and 30 % of large grains, respectively. The closer the grains are to the sphere, the closer the material is stacked, and the smaller the porosity value is. The grain size ratio has a significant effect on the minimum porosity of the mixture and the minimum porosity increases with the increase of the grain size ratio. The porosity of gap graded natural sand obtained by numerical method is accurate, and the error is within 10 %. The hydraulic conductivity is obtained by deriving fluid grid information and the results show that the simulated value of hydraulic conductivity is highly matched with the experimental value, and the error range is roughly between 10 % and 30 %.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
